The Spanish family that died in a helicopter crash in New York was celebrating a birthday when the accident occurred, a US official said on Saturday.

Senior Siemens executive Agustin Escobar died on Thursday after the sightseeing helicopter in which they were travelling plunged into the Hudson River.

Jersey City mayor Steven Fulop confirmed on his X handle that the family was celebrating the 40th birthday of Agustin Escobar's wife.

Fulop said, "A little context + I’m sharing this bc life moves quick + we don’t always think about the fact it is unpredictable + extremely fragile. On the helicopter crash."

"The Husband was here for a business trip + the family flew out to extend the trip a couple days in NYC. They were celebrating the mom’s 40th bday with the tourist helicopter flight yesterday. The kids were all 11 yo and younger. The brother in law is flying in this AM + we are working with ME to expedite release of the family to fly back to Spain. Take a moment today + think about this family + your family. These situations are always very difficult + sad," he said.

Apart from the family, the pilot of the helicopter died in the fatal crash.

The exact cause of the crash is still unknown.

'Highly Predictable'

An advocates group, which has been calling for the closure of the region's three heliports to non-essential traffic, said Thursday's crash was 'entirely predictable and preventable'.

“A lot of these helicopters are 30 or even 40 years old, and this one was 21 years old, which is still pretty old,” Andrew Rosenthal, the chair of the Stop the Chop group that has campaigned for an end to helicopter sightseeing trips over New York City and the New York-New Jersey metropolitan area, told The Guardian.

“In New York if you have a yellow cab you have to get a new one every five to eight years, yet here we are letting these things fly in the sky at 30 and 40 years of age. There’s no age limit that I’m aware of, which is crazy," he said.

“This was entirely predictable and preventable. If we had a rollercoaster that killed people every two years, we would not keep it operating, yet we have the same kind of joy ride in the sky that kills people every couple of years, and we keep changing nothing,” he said.